The difference between frequency and adaptation in evolution.
In a neat little series giving potted answers to various tricksome questions, NewScientist takes a look at the meaning of evolution. What happens a lot is that circumstances lead to certain genes in a species appearing more often in successive generations. The frequency of that gene has gone up but the fitness of the relevant species has not. Nonetheless, this falls into the category of evolution. The less frequent development is a mutation of a gene that is actually able to increase the fitness of the species. The frequency of this gene also goes up but in addition and as a result the species has adapted. This is evolution with improvement. It still does not mean that there is an end-goal out there for the species in question. Evolution continues to be random.
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